Paper separating mechanism and method



Sept. 19, 1961 R. c. SLATE 3,000,630

PAPER SEPARATING MECHANISM AND METHOD Filed Dec. 29, 1960 INVENTOR. P055197 6. 52/172 mu-u MW 3,000,630 PAPER SEPARATWG MEQHANISM AND METHOD Robert C. Slate, 1101 Emerson St, Seattle, Wash.

Filed Dec. 29, 1960, Ser. No. 79,331 14 Claims. (Cl. 271--64) This invention relates to sheet separating devices, and more particularly relates to statically located and automatically operating apparatus for separating thin superimposed sheets of material such as paper, as they are delivered together along a plane of feed through conveying and/or processing equipment. In a typical embodiment, as herein disclosed, such a sheet separating device and the related manipulative method have especial application to the problem of automatically separating the positive and negative sheets of photocopy paper as they are being fed to the developing tank in copy reproduction equipment such as a photocopyer.

Heretofore, customary design and operating technique with respect to so-called wet process copy reproduction equipment such as a photocopier have involved initial exposure of the negative paper to the original with the original with the original sandwiched between the posi tive and negative paper, after which exposure it has been necessary for the operator of the equipment to manually separate the leading edges of positive and negative sheets of paper before feeding them into the developing section of the machine.

This type of machine, performing a so-called twostep process, first receives the original to be copied in place between a sheet of negative paper and a sheet ofpositive paper, and the three sheet assemblage is rolled into the machine past an exposure light, then out of the machine. Then, as the second step, the original is removed and the positive and negative sheets are again fed into the machine and passed through a tank of developing fluid, after which they are pressed together and emerge from the machine. In performing the second step, it is important to deliver the positive and negative sheets into the developing tank in a separated condition so that the developing fluid can have full access to the negative. For this reason, it is customary to provide at the infeed point of the machine a split guide assembly with parallel slot-like guides which requires the user of the equipment to separate the two sheets in the process of reinserting them into the machine.

Such customary separation requirement occurs at an unfortunate time in the copying procedure, in that the quality of the copy reproduced is adversely affected if the light-sensitive negative is exposed to the room light unduly long during the manual manipulation required for reinsertion of the sheets into the machine. Manual separation also tends to conceal the leading edge of the bottom sheet, because of the operators angle of view thereof, which creates a problem in registration of the sheets and occasionally results in the sheets being inadvertently inserted at a slight oblique angle, causing the sheets to work themselves to one side of the internal feed mechanism, where they becomershredded or crumpled by the side walls of the machine. The critical nature of this manual manipulation procedure in the conventional machine mitigates against its use by un- -skilled persons, and thus limits the general utility of this type of equipment.

Some attempts have also been made to realize automatic internal separation of the positive and negative sheets in photocopy equipment, to provide what is known as a one-step process. However, all known prior mechanisms addressed to the problem of separating two sheets being fed together to a developing tank or the like have involved movable separatorelements which are rather intricate in operation, such as disclosed in Van Den ted rates Par a Brock 2,317,665 and Breuers et al. 2,947,539, or pneumatic manipulating devices such as the air jet shown in Schulze 2,766,044, or an oblique knife edge requiring special paper forms, such as disclosed in Baril, Jr. et al. 2,731,263.

In contrast to such prior paper separator devices, the mechanism and method of the present invention involves simple, static, compact, reliable and easily adjustable paper separating elements readily adaptable to be a simple modification in existing photocopy equipment, and fully capable of providing automatic paper separation in onestep type of photocopy machines without design complications as to any requirement for additional moving parts. operating technique which is considerably simplified over that required in operating a conventional two-step process machine, improving paper quality because of reduced unwanted exposure time, and rendering the equipment easier to use, in terms of operator dexterity. In addi-' tion, the static paper separating mechanism and method characteristic of the invention requires no special paper form, and does not mark, crease, or otherwise adversely affect the quality of the copy produced by the equip ment. Further, in providing automatic separation of the positive and negative sheets internally of the machine and immediately prior to the time the sheets enter the developing tank, the mechanism and method of the pres ent invention eliminates all need for even an awareness by the operator of the separation of the sheets as such enter the developing tank, and also permit external simplification of the equipment in that the separator plate assembly heretofore required is eliminated.

These and other objects, features, advantages and characteristics of the present invention will be apparent to those skilled in the art to which the invention is addressed from the following detailed description of a typi-' cal and therefore non-limitative embodiment thereof, taken together with the accompanying drawings, wherein like figures refer to like parts, and wherein: 1

FIG. 1 is a fragmentary isometric View of ini'eed roll and separator mechanism as associated with a typical photocopier developing tank; FIG. 2 is a fragmentary cross section of the assemblage as shown in FIG. 1; and

FIG. 3 is an enlarged, somewhat diagrammatic, detail view taken in the direction of feed of the sheets through the infeed roll means, to illustrate and further explain the separation action incurred by the mechanism of the invention.

With particular reference to the accompanying drawings, it will be understood that a representative applica tion of the invention in photocopy equipment can suitably involve components conventional per se including a developing tank T containing development fluid F and a wire form W which serves to receive the immersed positive and negative sheets P and N and support said v sheets slightly above any residue in tank T while the sheets are immersed in fluid F, and also guide said sheets out of the developing tank T at the discharge end thereof (not shown), after which the sheets are picked up by outfeed roll means (also not shown) and discharged from the machine. As will also be understood, such machine also includes, in a manner generally conventional per se, infeed roll means R, rotated in the directions indi: cated by arrow designations thereon, and of any suitable construction (the lower roll R being rubber and the upper roll R being metal, as shown, for example). Sheets N and P, when fed. through said rolls R, move in what maybe termed a plane of feed, or more specifically an initial plane of feed, the infeed direction of said sheets N and P being indicated at FIG. 2 by arrow designation 1). The infeed means typified by rolls R can beof any suit Further, such mechanism and method enable an able form as long as a plane of feed generally downwardly into tank T and somewhat above tank T is provided, it being also common practice in copy reproduction equipment to provide a series of longitudinally spaced pairs of roll means across the sheets, and/or roll means wherein both of a pair of rollers R either metal or resilient materials such as plastic or rubber. A simple slot guide can also suffice in certain situations as the infeed means, in which case the sheets N and P are simply hand fed into and through the paper separating mechanism.

The other paper handling and processing components of copy reproduction equipment are in no way modified or affected by the present invention, and such as therefore omitted from the accompanying illustrations, for clarity and simplicity, in that persons familiar with the construction of such equipment will readily perceive their relation to the mechanisms shown.

To the paper sheet handling and processing environment provided by roll means R and developing tank T, the paper separating mechanism of the present invention provides means for automatically separating the sheets N and P between the time they emerge from feed means R and the time they we immersed in the fluid F in tank T. To this end, the specific paper separating mechanism illustrated in the accompanying draWings involves a preferably but not necessarily all-plastic assemblage including a spaced pair of support plates lit) and 12 respectively situated above and below the initial plane of feed of paper sheets N and P, and spanning at least the width of said sheets. In the form shown, said support plates and 12 are joined by struts l4 and 16 at substantially the ends thereof, and the ends of plate 10 removably rest in angled slots in brackets mounted at the sides of tank T, one such bracket 18 and slot 20 being shown at FIGS. 1 and 2. By this arrangement, it will be seen that plate 10 is therefore directly supported by such brackets, and plate 12 is in turn held in fixed relation in tank T by its connection through struts 14 and 16 to plate 10.

Mounted to the underside of support plate 16 generally centrally thereof is a first separator rod 22, arranged with its longitudinal axis generally parallel to and slightly above the plane of feed of sheets N and P, and which terminates at its end toward the direction of feed of said sheets in a guide surface 24 disposed at an angle of about 45 with respect to the plane of feed of sheets N and P, the said guide surface 2d being of elliptical form by reason of the angle cut in rod 22. Said guide surface 24, by such angle of cut, presents a pointed edge 26 situated just above said plane of feed. Pointed edge as is the separation point around which sheets N and P are guided by the mechanism.

Extending generally laterally and at somewhat diverging directions from rod 22 are a pair of post-separation guide rods 28 and 30 which serve the beneficial function of supporting the side areas of the separated upper sheet P after said upper sheet P passes the guide surface 24, as more fully discussed below.

Lower support plate 12 mounts in the area thereof below rod 22 a mounting plate 32 which in function is essentially a part of said lower support plate 12. Said mounting plate 32, as shown, is disposed substantially parallel to and slightly below the plane of feed of sheets N and P, and in turn mounts a laterally spaced pair of lower separator rods 34 and 36, each with its longitudinal axis substantially normal to the plane of feed of said sheets N and P, and each terminating in respective guide surfaces 38 and 40 disposed at an acute angle of about 45 across said plane of feed, which guide surfaces 38 and 40 terminate in respective pointed edges 42 and 44 situated slightly above said plane of feed and slightly behind pointed edge 26 of the upper guide surface 24, with the said pointed edges 42 and 44 situated so that an 4 imaginary line therebetween intersects a portion of rod 22 proximately of guide surface 24 thereof.

As will be evident from the following detailed dmcription of the manner in which said guide surfaces 24, 38 and 40 manipulate the sheets N and P to separate same, the juxtaposition and relative arrangement of said surfaces with respect to the plane of feed of sheets N and P and with respect to each other are operatively important to realization of the separation action characteristic of the invention. As will be evident from the elemental relation shown, rods 34 and 36 are readily adjustable with respect to mounting plate 32 and consequently with respect to guide surface 24 and the plane of feed of sheets N and P, such as by friction fitting of said rods in mounting plate 32, by selective positioning and cementing of said rods in said plate 32, or by thread means (not shown) between said rods and mounting plate 32, as desired, to achieve and maintain the desired relation of said guide surfaces 38, 40 and 24.

in that rods 38 and 40 as shown are formed of round rod stock, and cut at an angle of about 45 to provide guide surfaces 38 and 40, it will be apparent that said guide surfaces 38 and 40 are elliptical in form.

The separator assembly shown at FIGS. 1 and 2 further comprises a support bar 46, the ends of which rest in slots in side brackets 18, one of which slots is indicated at 48, which support bar 46 in turn mounts a guide plate 50 spanning the tank T in spaced relation above upper support plate 10. Guide plate 50 and bar 46 serve to ensure downward deflection of separated sheet P in the fluid F of tank T. While it will be apparent such bar 46 and guide plate 50 are not functionally related to the paper separating components of the assemblage, such are preferably employed in conjunction with the paper separating elements as adapted to photocopy machine use to positively assure uniformity in the extent of immersion of sheet P in the developing fluid F, particularly where some of the sheets fed to the machine are relatively stiff.

"FIG. 3 serves to show somewhat diagrammatically the action of the guide surfaces in separating the sheets N and P, and represents a papers-eye view of the guide surfaces 24, 38 and 4t) as well as the respectively associated pointed edges 26, 42 and 44 of these surfaces. in considering the view of FIG. 3, it will be recognized that the guide surface 24 as viewed from the plane of feed appears circular even though such is actually elliptical in form, since rod 22 is being viewed endwise.

Relating the accompanying figures, and particularly FIG. 3, to the manner of operation of the paper separating elements shown, the two sheets N and P are inserted into the machine through a single slot infeed guide assembly (not shown) above infeed rollers R with the leading edge of lower sheet N preceding the leading edge of upper sheet P a slight amount, eg about of an inch, or even less, down to a minimum lead dimension of about ,5 inch if the finite offset separation between points 42 and 44 and surface 24, as viewed in FIG. 2, is very small. As sheets N and P are drawn through the infeed rollers R and proceed together toward guide surfaces 33 and 40, the respective feed lines FN and PP thereof fall substantially as shown at FIG. 3, and the initial attitude of the leading areas of sheets N and P fall in a plane tangential to the nip surfaces of rollers R, which plane geometrically falls substantially between feed lines FN and PP, and which for reference purposes is simply denoted the plane of feed.

When the leading edge of the lead sheet N engages guide surfaces 38 and 40, a series of events occur which result in a definite, positive separation of the sheets without any excess bending or pressure being applied to the sheets which might tend to crease, tear or otherwise jam them in the mechanism. Specifically, as the lead sheet N advances, guide surfaces 38 and 40 are contacted and the leading edge of said sheet N, and it as well as aooaeao the leading edge of'following sheet P aredeflected' some? what upwardly until the portion of the leading edge of sheet N between guide surf ices 38 and 40 engages thev lower face of rod 22 just behind pointed edge 26 thereof, which lower edge of rod 22 therefore is functionally an additional guiding surface. Such engagement of the; center portion of the leading edge of sheet N with the lower face of rod 22 causes slight relative downward deflection of such leading edge only as to the portion thereof between guide surfaces 38 and 40, and the leading edge of sheet N progressively rides up over pointed edges 42 and 44 with the central portion therebetween remaining in a downwardly deflected position, substantially as shown in FIG. 3 at DN. Then, as the leading edge of the following sheet P approaches the guide surfaces, the upwardly deflected portions of lower sheet N riding over pointed edges 42 and 44 in effect become guide surfaces for the leading edge of following sheet P, raising same above pointed edge 26 of guide surface 24 and the leading edge of said upper sheet P comes into engagement with guiding surface 24 at substantially the level shown in FIG. 3 at DP, whereupon progressive further feed of sheets N and P cause separation of said sheets around the separation point presented by pointed edge 26, and upper sheet P passes over upper support plate while lower sheet N passes between upper support 10 and lower support 12, typical positions of such sheets N and P at this stage being indicated at FIG. 2 in phantom and designated N and P.

The spaced separation between lower sheet N and upper sheet P provided by the undulation of sheet N realizes a spacing or separation 52 (FIG. 3) of a dynamic nature, audit is the essence of'the present invention that such separation or spacing 52 is met by a separation point or edge 26 around which the sheets separate. In observing the action of the guiding surfaces, it appears that the simultaneous upward and-downward deflection imparted to the leading edge of lead sheet N also causes what may be termed a slight but positive triangulation in the central portion of said sheet N, which augments the lifting and guiding of the following sheet P by the lead sheet N above and over pointed edge 26 and apparently aids in breaking the momentary vacuum pocket between the sheets. The rearward apex of the triangulation area appears to lift with a slight but rapid snap action which positively enhances to the reliability and a substantial range ofjuxtaposition to compensate for various weights and textures of paper, the general proposition in this regard of course being that stiffer paper can tolerate relatively wide finite separation between the various guide surfaces. Also, while the foregoing disclosure relates theseparating action to photocopy paper with the negative sheet N as the bottom sheet, it will be obvious that the sheets couldbe reversed, or be any otherwise constituted pair of like or dissimilar sheets of paper or similar flexible sheet material being manipulated by the separator mechanism. Likewise, with respect to possible design variations, it will be recognized that the guide surfaces 24, 38 and 40 need not necessarily be elliptical or circular in form, but could be rectangular, triangular, or simply thin sheet material on edge, so long as the indicated juxtaposition and action on the leading edges of the paper are accomplished. Evident, also, will be the possibility that the separator mechanism can be oriented upside down from the attitude shown, if a particular adaptation renders it necessary or desirable that the upper sheet of the infed pair be the lead sheet. Similarly, it will be understood that the precise angular relation of any one of the guide surfaces 24, 33 and 40 with respect to the plane of feed can be varied as desired, the important consideration in this respect being that said surfaces, particularly surfaces 38 and 40, do not lie so abruptly with respect to the plane of feed as to cause buckling of the leading edge of the lead sheet. In addition, while the separator mechanism of the invention has been illustrated and specifically discussed with respect to a two-step photocopy equipment adaptation thereof, it will be. readily appreciated by designers in any of the various arts involving paper handling and paper processing that many other applications for the separating elements are possible, and that the separating device has functional utility in any environment where sheets progressively fed together are to be automatically separated.

These and other modifications, variations, applications, and utilization environments as well as changes in form and construction, will readily occur to those skilled in the arts to which the invention is addressed, within the scope of the following claims.

What is claimed is:

1. A method of automatically separating two sheets of paper initially in face to face contact with one sheet slightly leading the other, comprising substantially simultaneously deflecting the central portion of the leading edge of the lead sheet in one direction away from the direction of feed of said sheets and deflecting side portions of said leading edge in the other direction away from said direction of feed, maintaining such central and side portions thus deflected to separate the leading edge of the following sheet slightly from the surface of the lead sheet while interposing a separation point between the leading edge of the following sheet and the adjacent, spaced surface of the lead sheet, and feeding said sheets around said separation point to cause complete separation thereof. i 5

2. A device for automatically separating two 'pape sheets fed together thereto along a plane of feed with one sheet slightly leading the other; comprising two laterally arranged guide elements disposed at an acute angle across said plane of feed to be encountered by and deflect laterally spaced portions of the leading edge of the lead sheet, a third guide element terminating in a separation point and situated between said two spaced guide elements, said-third guide .element being disposed to maintain the lead sheet portion between said spaced guide elements closer to said plane of feed than the portions thereof passing over said two guide elements, thereby lifting the following sheet portion between said two guide elements slightly above said lead sheet and providing a separation of the sheets around said separation point, whereupon the following sheet proceeds in a separated relation to the lead sheet as said sheets are progressively fed past said separation point.

3. A device for automatically separating positive and negative photographic sheets fed thereto in face-to face contact with one sheet slightly leading the other; comprismg a stationary apparatus having laterally juxtaposed guide elements including a centrally disposed surface deflecting the leading edge of the lead sheet under a central point and two guide surfaces deflecting laterally spaced portions of the leading edge of the lead sheet over two guide points adjacent to said central point and lifting the portion of the following sheet passing closest to said central point slightly thereabove to accordingly keep same from engaging said central point, whereupon the following sheet proceeds in separated relation to the lead sheet with separation occurring around said central point as said sheets are progressively fed through said apparatus.

4. In combination with means delivering two sheets of paper together along a plane of feed with the leading edge of the lower sheet slightly ahead of the other sheet; a static, automatic sheet separating mechanism comprising a pair of guide elements providing laterally spaced deflection surfaces disposed at an acute angle across and terminating slightly above said plane of feed to be encountered by and deflect portions of the leading edge aooaeso of said lower sheet relatively upwardly, a third guide element disposed between said pair of spaced surfaces and presenting upper and lower deflection surfaces starting at a pointed edge situated just above said plane of feed with the upper deflection surface thereof sloped at an acute angle with respect to said plane of feed, the said pointed edge of said third element being somewhat below the upper extent of the said pair of spaced deflection surfaces so that spaced portions of the leading area of the lower sheet of paper are deflected relatively upwardly by said spaced pair of surfaces and the portion of said lower sheet between such spaced portions thereof is defiected relatively downwardly by the lower deflection surface of said third element, such deformation raising the leading edge of the upper sheet to a level above the point of said third element so that the upper sheet encounters only the upper deflection surface of said third element and is separated from said lower sheet as said sheets are progressively fed past said elements by such sheet delivering means.

5. The combination of claim 4, wherein the said pair of spaced surfaces are disposed at an angle of about 45 with respect to said plane of feed.

6. An automatic paper separating means for separating positive and negative photographic sheets in a photocopy machine and the like, comprising means feeding said sheets in face to face contact with one sheet slightly leading the other, a stationary separating apparatus comprising three guide surfaces presenting a central guide point and two, laterally spaced guide points, one at each side of said central point, the side points having guide surfaces leading thereto which are disposed at a substantial acute angle across the plane of feed of said sheets into said stationary apparatus, the said central point having a guide surface leading divergingly therefrom and also crossing said plane of feed, said three points and such associated guiding surfaces serving to deflect the leading edge of the lead sheet downwardly in its central portion and upwardly in its side portions, laterally considered, the leading sheet thus deflected along with the side points disposed slightly above said plane of feed serving to lift the following sheet above said central point to separate said sheets around said central point as said sheets are fed through said apparatus.

7. in combination with roll infeed means delivering two sheets of paper together along a plane of feed with the leading edge of the lower sheet slightly ahead of the other sheet; a static, automatic sheet separating mechanism comprising a spaced pair of support plates relatively situated respectively above and below the initial plane of feed of said paper sheets to said mechanism and spanning the width of said sheets, a first separator rod situated substantially centrally of such upper plate and extending longitudinally above said plane of feed, said rod terminating in a guide surface having a pointed edge at a location just above said plane of feed and extending at an acute angle upwardly therefrom, laterally spaced guide surfaces supportably mounted on said lower support plate and presenting deflection surfaces to said plane of feed with pointed upper extremities situated slightly above said plane of feed and slightly behind the pointed edge of said first guide surface along the direction of feed of said sheets, the lower of said sheets in encountering such spaced pair of guide surfaces after passing under the pointed edge of said first guide surface being formed into an undulated pattern, the raised portions of which lift the leading edge of the upper sheet above the pointed edge of said first guide surface, causing separation of said sheets around said pointed edge, the upper sheet thereafter passing over said upper support plate and the lower sheet thereafter passing between said upper support plate and said lower support plate.

8. The combination of claim 7, wherein the said spaced guide surfaces supportably mounted on said lower support plate are disposed at an angle of about 45 with respect to said plane of feed.

9. The combination of claim 7, wherein said support plates span a photocopy machine developing fluid containing tank slightly above the liquid level thereof, and a third plate spanning said tank is provided in spaced relation above said upper support plate to insure downward deflection of the separated, upper sheet into the fluid in the tank.

10. The combination of claim 7, wherein said first guide element is a round rod cut at its end toward the direction of feed of said sheets atan angle to provide said pointed edge and a substantially elliptical guide surface above the initial plane of feed of said sheets.

11. The combination of claim 7, wherein said paper separating guide surfaces are substantially elliptical in form.

12. The combination of claim 7, wherein the guide elements providing said laterally spaced guide surfaces as supported by said lower support plate comprise two rod forms arranged with their longitudinal axes substantially normal to said plane of feed, each cut at an angle to provide along such cuts substantially elliptical guide surfaces with pointed upper edges situated slightly above said plane of feed.

13. The combination of claim 12, wherein each of said rods is individually adjustable as to the attitude of its guide surface with respect to said plane of feed.

14. The method of automatically separating two sheets fed together in face to face contact along a plane of feed with one sheet slightly leading the other, comprising substantially simultaneously deflecting one portion of the leading edge of the lead sheet in one direction away from the direction of feed of said sheets and deflecting other portions of said leading edge in the other direction away rorn said direction of feed to deflectingly separate the leading edge of the following sheet slightly from the surface of the lead sheet, interposing a separation point between the leading edge of the following sheet and the adjacent, spaced surface of the lead sheet, and feeding said sheets around said separation point to cause complete separation thereof.

No references cited. 

